Circuit tape having adhesive film, semiconductor device, and a method for manufacturing the same

ABSTRACT

A semiconductor device having a superior connection reliability is obtained by providing a buffer body for absorbing the difference of thermal expansion between the mounting substrate and the semiconductor element in a semiconductor package structure, even if an organic material is used for mounting substrate. A film material is used as the body for buffering the thermal stress generated by the difference in thermal expansion between the mounting substrate and the semiconductor element. The film material has modulus of elasticity of at least 1 MPa in the reflow temperature range (200-250° C.).

This application is a Divisional application of application Ser. No.08/857,674, filed May 16, 1997 now U.S. Pat. No. 6,114,753.

BACKGROUND OF THE INVENTION

The present invention relates to a circuit tape, a semiconductor device,and a method of manufacturing the same, which are superior in electricalcharacteristics, mounting reliability, and assembling easiness, and areresponsive to the requirements for high density mounting, multipinsmounting, and fast transmittance.

Currently, in the continuing effort to improve electronic devices toprovide high performance, the demand for high integration and highdensity mounting of semiconductor elements has become strong. Therefore,semiconductor elements have been improved to achieve high integrationand high performance, such as in LSI, VLSI, and ULSI devices, and therehas been increase in the capacity, the number of pins, the speed, andpower consumption thereof. In responding to such advances, the packagestructure of the semiconductor device for multipins has been changedfrom a structure, in which connecting terminals are provided at twosides of the semiconductor element, to an advanced structure, in whichthe connecting terminals are provided at all four sides of thesemiconductor element. Furthermore, in order to respond to increasingthe number of pins, a grid array structure has come to be used inpractice. The grid array structure is a structure of a semiconductorelement, in which the connecting terminals are provided in a grid arrayover the entire mounting surface of the semiconductor element by using amultilayer carrier substrate. The grid array structure includes a ballgrid array structure (BGA), which has a shortened connecting terminallength in order to make fast signal transmission possible. The ball typestructure of the connecting terminal increases the width of itsconductor; therefore, the ball structure is also effective in decreasinginductance. Currently, in order to respond to the requirement for fastsignal transmission, organic materials haying a relatively lowdielectric constant have been investigated for use in the multilayercarrier substrate. However, the organic materials have generally alarger thermal expansion coefficient than the semiconductor element, andso thermal stress generated by the difference in thermal expansionbecomes a problem from the point of view of connection reliability, andso on. Recently, a structure which does not use a carrier substrate hasbeen proposed for the BGA package.

More particularly, a new semiconductor element package structure hasbeen disclosed (U.S. Pat. No. 5,148,265), in which the connectionreliability is improved by using an elastomer material having a lowmodulus of elasticity for reducing the thermal stress generated by thedifference in thermal expansion between the semiconductor element andthe mounting substrate. The proposed package structure uses a circuittape composed of a polyimide and the like, instead of a carriersubstrate, for electrically connecting the semiconductor element and themounting substrate. Therefore, the electrical connections between thesemiconductor element and the circuit tape are effected by a wirebonding method or a bonding connection with leads, and the circuit tapeand the mounting substrate are electrically connected by soldering ballterminals. As the elastomer material of the prior art, a siliconematerial is generally used since this is a material having a low modulusof elasticity and a superior heat resistance. As a general method forforming a stress buffer layer with a silicone material, the steps ofprinting an uncured liquid resin on the circuit tape using masks, andsubsequently, curing the printed resin, are generally used. However, theabove method has problems, such as a difficulty in maintaining theflatness of the buffer layer obtained by the printing, and thecomplexity of the printing process, which requires a long time for theprinting, is disadvantageous. Accordingly, the above method is notsuitable for a mass-production process, and so the problems whichundesirably affect the assembling yield and reliability of mountingcaused by the difficulty in maintaining the flatness of the buffer layerare yet to be solved.

SUMMARY OF THE INVENTION

One of the objects of the present invention is to provide a method ofobtaining a stress buffer layer which is superior in flatness by using afilm material as the elastomer material for reducing the thermal stressin the semiconductor devices, thereby obtaining semiconductor deviceswhich are superior in mass productivity.

In order to realize the above object, the present invention provides thefollowing measures.

The measures can be achieved by providing a semiconductor devicecomprising a circuit tape having a pattern layer connected electricallyto a semiconductor element, an external terminal provided on the circuittape for electrically connecting the circuit tape to a mountingsubstrate, and film material for causing the circuit tape to adhere tothe semiconductor element while maintaining an insulation conditionbetween the circuit tape and the semiconductor element, wherein the filmmaterial for effecting the adhering has a physical property such thatthe modulus of elasticity of the film material in the temperature rangeof a solder reflow condition for mounting (200-250° C.) is at least 1MPa.

The above film material for effecting the adhering is passed through aprocess for forming an external terminal, such as a solder ball and thelike, for connecting the mounting substrate and the circuit tape, or asolder reflow process for mounting the semiconductor element of thepresent invention onto a mounting substrate in the manufacturing processof the semiconductor devices. The reflow temperature is generally a hightemperature in the range of 200-250° C. Therefore, if the semiconductordevice contains moisture, the moisture evaporates during the heattreatment, and the film material swells due to the vapor pressure of themoisture. When the swelling exceeds a threshold value, a foamingphenomenon is generated, and defects, such as void formation,delamination, and the like, are generated. Therefore, the film materialto be used is required to have as low a moisture absorption rate aspossible and a high modulus of elasticity in the range of the reflowtemperature. In accordance with the present invention, various filmmaterials have been studied, and it was found that the adhesivematerials having a modulus of elasticity in the temperature range of areflow process of at least 1 MPa had superior reflow characteristics.Several examples of the temperature dependence of the modulus ofelasticity of the material are shown in FIG. 1.

Furthermore, it was found that when materials, of which the modulus ofelasticity in the temperature range of the mounting reflow condition wasmaintained at least at 1 MPa, were used, a preferable result in theanti-reflow characteristics could be obtained. The amount of swellingdepends on the ratio of the vapor pressure and the modulus ofelasticity, and the higher the modulus of elasticity is, the less willbe the amount of swelling. The foaming phenomenon is generated when theamount of swelling exceeds the break elongation, one of the mechanicalproperties of the material. Furthermore, the modulus of elasticitycorrelates with the mechanical strength of the adhesive film material,and generally, the higher the modulus of elasticity is, the greater willbe the tendency to increase the break stress and break elongation.Therefore, by using a material having a high modulus of elasticity inthe range of the reflow temperature, the reflow characteristics can beimproved as to both the swelling amount and the mechanicalcharacteristics. In the above case, the adhesive film material may beeither a thermosetting resin or a thermoplastic resin.

The adhesive layer is sometimes composed of either sticky adhesiveagents or sticky-cohesive adhesive agents, in addition to the adhesiveagents made of the above material. In order to maintain the modulus ofelasticity at least at 1 MPa in the temperature range of the reflowprocess, the thermoplastic resin preferably has a glass transitiontemperature, i.e. a changing point of modulus of elasticity, which ishigher then the temperature range (200-250° C.) of the reflow process.The thermosetting resin is required to have a chemical or physicalcrosslinking structure to a certain degree at a temperature in therubber region, which is higher than the glass transition temperature.That is, the modulus of elasticity in the rubber region is generallyproportional to the crosslinking density, and the crosslinking densitymust be increased in order to increase the modulus of elasticity. Thefilm material is desirably composed of a resin having a low modulus ofelasticity which is at the utmost 4000 MPa at room temperature, in orderto operate as a stress buffer layer.

As one of characteristics of a film material, the coefficient ofmoisture absorption at 85° C./85% RH for 168 hours is desirably, at theutmost, 3% in view of the reflow characteristics. As the film material,materials having a low modulus of elasticity, except for a siliconematerial, can be used. The structure of the film material is notrestricted to a homogeneous structure composed of an adhesive agentcomponent, but also, for instance, a three layer structure havingadhesive layers at both surfaces of a supporter, respectively, or astructure in which the adhesive agent is impregnated into a poroussupporter, can be used. As shapes of the film, various shapesmanufactured by stamping, a mesh-like shape, and the like can be used.The mesh-like shape is effective in improving the anti-reflow propertyat the moisture absorbing time, because the adhesion area can bedecreased.

In the case of a multilayer structure represented by a three layerstructure, the supporter and the adhesive layer can be composed of acombination of at least two kinds of the above adhesive agents, thesticky adhesive agents, the sticky-cohesive adhesive agents, and thelike. The adhesive layer is located at each of both of the surfaces ofthe supporter, and each adhesive layer can be formed of a different kindof material from the other. For instance, a combination is usable inwhich a thermosetting resin having a high fluidity is used in order toflatten or eliminate the unevenness of the pattern layer of the circuittape side, and a thermoplastic resin, which can be adhered in a shorttime at a high temperature, is used at the opposite flat portion foradhering to the semiconductor element.

A set of schematic illustrations indicating a flow of a generalfabrication process for the manufacture of semiconductor devices,according to the present invention, is shown in FIG. 2.

The process an be divided into three representative sections. The firstone, including STEPS 1-5 (2-a), is a method for fabricating asemiconductor element comprising (1) the step 1 of applying an adhesivefilm 2.2 to the tape 2.1 having a pattern layer and a wire 2.1.2 to tape2.1, (2) the step 2 of adhering the tape 2.1 having a pattern layer tothe semiconductor element 2.3 having the pad 2.6 by means of theadhesive film 2.2 while maintaining an insulating conditiontherebetween, (3) the step 3 of electrically connecting the patternlayer formed on the tape 2.1 and the pad 2.6 on the semiconductorelement 2.3, via connecting lead 2.1.1′, formed from wire 2.1.1, (4) thestep 4 of sealing the electrically connected portion with an insulatingagent (e.g., mold resin) 2.4, and (5) the step 5 of forming an externalterminal 2.5 on the tape for connection to the mounting substrate.

The above method is effective in improving the processability, becausethe circuit tape and the film material can be handled in the manner of areel to reel process, as will be explained later.

The second one, including STEPS 6-10 (2-b), is a method for fabricatinga semiconductor element comprising (1) the step 6 of applying anadhesive film 2.2 to the semiconductor element 2.3 having pad 2.6, (2)the step 7 of adhering the tape 2.1 having a pattern layer to thesemiconductor element 2.3 by means of the adhesive film 2.2 whilemaintaining an insulating condition therebetween, and adhering wire2.1.1 to tape 2.1, (3) the step 8 of electrically connecting the patternlayer formed on the tape 2.1 and the pad 2.6 on the semiconductorelement 2.3 via connecting lead 2.1.1′, formed from wire 2.1.1, (4) thestep 9 of sealing the electrically connected portion with an insulatingagent 2.4, and (5) the step 10 of forming an external terminal 2.5 onthe, tape 2.1 for connection to the mounting substrate.

The above method is effective in improving the production yield of thesemiconductor element itself. In accordance with the method, the stressbuffer layer can be formed on the semiconductor element at the waferstage condition.

The third one, including STEPS 11-14 (2-c), is a method of fabricating asemiconductor element comprising (1) the step 11 of setting the tape 2.1having the pattern layer in registration and adhering the tape 2.1 tothe semiconductor element 2.3 having pad 2.6, using the adhesive film2.2 simultaneously with maintaining an insulating conditiontherebetween, and adhering wire 2.1.1 to tape 2.1 (2) the step 12 ofelectrically connecting the pattern layer formed on the tape 2.1 and thepad 2.6 on the semiconductor element 2.3 via connecting lead 2.1.1′,formed from wire 2.1.1, (3) the step 13 of sealing the electricallyconnected portion with an insulating agent 2.4, and (4) the step 14 offorming an external terminal 2.5 on the tape 2.1 for connection to themounting substrate.

The above method is effective in shortening the manufacturing time,because the number of steps in the process can be decreased.

These methods essentially comprise the following steps. The adhesivefilm material of the present invention is provided between the tapematerial having the pattern layer and the semiconductor element byadopting a certain method, and the tape material and the semiconductorelement are bonded together simultaneously or sequentially underconditions of designated temperature, pressure, and time. Subsequently,the pattern layer on the tape is electrically connected to theconnecting pad of the semiconductor element. As examples of a connectingmethod using a connecting lead previously formed on the circuit tape asa circuit for connection with the semiconductor element, any one of asingle point bonding method, a gang bonding method, and the like can beused.

As another example of a method for connection, a method in which thepattern layer and the semiconductor element are connected with wirebonding can be adopted.

Then, the connecting portion is encapsulated with an insulatingmaterial, and finally the external terminals, which are electricallyconnected with the mounting substrate, are formed on the circuit tape.As an external terminal, a solder ball is generally used, and most ofthe solder ball is formed by plating. Metals which may be used for theplating are gold, nickel, copper, solder, and the like.

In order to improve the mass productivity in the manufacturing process,the process for integrating the adhesive film material with the circuittape previously as shown in FIG. 2a is important.

As a general method for the above process, a method comprising the stepsof transferring the tape, whereon the pattern is formed, by a long reelapparatus, stamping out the adhesive film into a designated shape, andadhering the adhesive film of the designated shape onto the circuittape, as shown in FIG. 3, is effective for mass production. Shown inFIG. 3 is reel 3.1 for the long circuit tape and reel 3.2 for theadhesive film. Punching jig 3.3, and adhesive film 3.4 on the circuittape, are also shown in FIG. 3. When the adhesive film is made of athermosetting resin, the adhesive film can be made to adhere to thecircuit tape while in an uncured A stage or a half-cured B stage. Theresin is then further cured to a condition of a final-cured C stageduring the step of adhering the obtained circuit tape, to which theadhesive film is attached, to the semiconductor element. Otherwise, ifthe adhesive agent reaches the condition of the final cured C stageduring the time that the adhesive film is adhered to the circuit tape,sometimes, an adhesive layer is newly formed on the cured film portion.

As a method for forming the adhesive layer, an application method, afilm adhering method, and the like are generally used. The adhesivecomponent is desirably not sticky at room temperature, but if sticky, amold releasing paper and the like is used.

FIG. 4 shows an example of the composition of a circuit tape to which anadhesive film is attached. The circuit tape 4.1 can be adhered to thesemiconductor element 4.3. If a thermosetting resin is used for theadhesive layer 4.2 at the circuit tape side and a thermoplastic resin isused for the adhesive layer (not shown in FIG. 4) at the side adhered tothe semiconductor element, the circuit tape having the adhesive abilityshown in FIG. 4 can be provided readily. Wire 4.1.1 is electricallyconnected to circuit tape 4.1.

When the adhesive layer is composed of a thermoplastic, sticky, orcohesive material, the conditions for the two steps to adhere to thecircuit tape and to the semiconductor element can be set as quite thesame with respect to each other. As opposed to the case of athermosetting resin, the curing reaction does not need to be controlledat the intermediate stages, and so a manufacturing process superior inworkability can be provided.

When the adhesive layer is composed of a sticky or cohesive material,the material is advantageous from the point of view of avoiding warpageof the semiconductor element, because the material can be adhered atroom temperature. When the adhesive film is initially combined with thecircuit tape, the semiconductor element is easily registered at the timeof adhering to the circuit tape. Accordingly, the jigs of the adheringapparatus can be simplified, and the method becomes advantageous formass production.

With the semiconductor device relating to the present invention, theunevenness of the pattern circuit on the circuit tape is sometimeseliminated by filling spaces with the adhesive layer of the film. Inthis case, the suitability of the adhesive layer for the filling can beconfirmed at the step of combining the circuit tape and thesemiconductor element. Therefore, an unsuitable adhesive layer can beeliminated before joining the circuit tape to the semiconductor element,a loss of the semiconductor can be avoided, and an advantageous increasein the production yield can be attained.

Typical examples of a thermosetting resin and a thermoplastic resin forthe adhesive component of the film materials are as follows: epoxyresin, polyimide resin, polyamide resin, cyanate resin, isocyanateresin, fluorine-containing resin, silicon-containing resin, urethaneresin, acrylate resin, styrene resin, maleimide resin, phenolic resin,unsaturated polyester resin, diallyl phthalate resin, cyanamide resin,polybutadiene resin, polyamideimide resin, polyether resin, polysulfoneresin, polyester resin, polyolefine resin, polystyrene resin, polyvinylchloride, transpolyisoprene resin, polyacetal resin, polycarbonateresin, polyphenylene ether resin, polyphenylene sulfide resin,polyacrylate resin, polyether imide resin, polyether sulfone resin,polyether ketone resin, liquid crystalline polyester resin,polyallylether nitrile resin, polybenzoimidazole resin, various kinds ofpolymer blend, and polymer alloys, and the like.

The above examples of a thermosetting resin and a thermoplastic resininvolve materials having an adhesiveness resulting from melting orsoftening of the material by heating. On the contrary, the sticky orcohesive materials are materials having an adhesiveness produced bypressurizing.

Typical examples of the sticky and cohesive materials are as follows:various rubber groups, such as the silicone group, the butadiene groupand the isoprene group, acrylate groups, polyvinyl ether groups, and thelike. The cohesive material includes a room temperature curing type, atype cured by heat, ultraviolet ray irradiation, electron beamirradiation, and the like, a type cured by concurrent use of anaccelerator, and the like. The room temperature curing type includes amoisture-reactive type which reacts in the presence of moisture in theatmosphere, a photo-reactive type which contains a photo-initiator, andan anti-oxygen material which contains peroxide, and the like. Thethermosetting resin generally includes a crosslinking agent, such asthiurum groups, phenol groups, isocyanate groups, and the like, andadhesive components are crosslinked three-dimensionally to form theadhesive layer at a designated temperature.

The material of the type cured by ultraviolet ray irradiation, orelectron beam irradiation, contains various photo-initiators. Thematerial of the type cured by concurrent use of an accelerator includesa solution containing a reaction accelerator and a crosslinking agent,which are applied onto the surface of the sticky layer, wherein theadhesive layer is finally formed by mixing the above two agents with acontact pressure and reacting the two agents sequentially. For thecohesive agent of the present invention, a thermosetting resin isrelatively preferable. Using a thermosetting resin, a semiconductordevice, which is superior in mass productivity and reliability, can beprovided by the method comprising the steps of registering the circuittape and the semiconductor element at room temperature, bringing thewiring tape and the semiconductor element into contact to form a set,and elevating the temperature of a plurality of such sets to adesignated degree simultaneously in a container, such as a constanttemperature bath, for producing a curing reaction to ensure the adhesivestrength.

The modulus of elasticity of the adhesive film material is preferablyhigh at a high temperature region in view of the reflow characteristics,but as low as possible at room temperature. In this regard, thesemiconductor element and the mounting substrate generally havedifferent thermal expansion coefficients from each other, and a thermalstress is generated, when the mounting is performed, at the externalterminal, which is composed of a solder ball and the like. Then, thereliability of the connection becomes remarkably important.

If the modulus of elasticity of the adhesive film existing between thesemiconductor element and the mounting substrate is low, the region ofthe adhesive layer becomes a stress buffer layer, and this isadvantageous from the point of view of the connection reliability. Themodulus of elasticity at room temperature is desirably, at the utmost,4000 MPa. More preferably, the modulus of elasticity in the entire rangeof the heat cycling test (−55° C.-150° C.) is, at the utmost, 2000 MPa.As a material which has a high modulus of elasticity at a hightemperature and a relatively low elastic modulus in a range of a lowtemperature including room temperature, sometimes silicone groupmaterials are used. A film material comprising a silicone group materialis one of the significantly important materials of the presentinvention.

However, film materials, other than the silicone group material havingthe above characteristics, are advantageous in comparison with thesilicone group material. That is, because of the weak cohesive energy ofsilicon, cyclic low molecular weight silicone group compounds aregradually decomposed thermally during a long heat treatment, such asduring storing at a high temperature (for instance, at least 150° C.),and this sometimes becomes a cause of contamination to the environment.

The composition of the film material of the present invention is notonly a homogeneous structure composed of the adhesive agent components,but also may be a three layer structure, such as a supporter havingadhesive agent layers at both surfaces for instance, and a structure inwhich the adhesive agent is impregnated into a porous supporter. As thesupporter of the film material, films or a porous material made ofpolyimide, epoxy, polyethylene terephthalate, cellurose, acetate,fluorine-containing polymer, and the like can be used.

As the shape of the film, the various shapes obtainable by stamping out,a mesh-like shape, and the like can be used. The mesh-like shape iseffective in improving the anti-reflow properly at the moistureabsorbing time, because the adhesion area can be decreased. The threelayer structure can be controlled to an arbitrary thickness and as tothe kind of the adhesive layer provided at both the surfaces of thesupporter, and the fluidity of the adhesive layer at the time ofadhesion can be readily controlled. Furthermore, the presence of aninsulating layer is ensured by the supporter located between theadhesive layers.

The value of vapor pressure of the adhesive material by moistureabsorption at the time of reflow can be maintained at a low value byusing the material, of which the film material has a coefficient ofmoisture absorption at 85° C./85% RH of, at the utmost, 3%, and sopreferable reflow characteristics can be obtained.

The tape having a pattern layer is generally composed of a flexiblecircuit substrate. That is, a polyimide group material serving as theinsulating layer, an epoxy group material, a polyimide group material, aphenolic group material, a polyamide group material, and the like areused as the adhesive layer with the conductor. Generally, copper is usedas the conductor. As the wiring circuit, the copper is sometimes coatedwith nickel, gold plating, and the like. As the flexible circuitsubstrate, a material, which does not use the adhesive layer with theconductor, but uses a copper layer formed directly onto the polyimideinsulating layer, is sometimes used.

The tape having a pattern layer is sometimes composed of a multilayerwiring structure. In this case, a voltage layer, a ground layer, and soon in addition to the signal layer can be formed in the circuit tape,and so a semiconductor device which is superior in electriccharacteristics can be provided.

Two typical arrangements of the pad terminal on the semiconductorelement for electrically connecting the tape material having the patternlayer with the semiconductor element are as follows.

The one is a peripheral pad arrangement as shown in FIG. 5. FIG. 5 showssemiconductor element 5.1 and pads 5.1.1. In this case, there aredifferent types of structure for the arrangement of the externalterminal of the semiconductor device, as shown in FIGS. 6-1, 6-2, 6-3.That is, the case wherein the external terminals are located under thesemiconductor element 6.3 (Fan In type, FIG. 6-1), the case wherein theexternal terminals are located outside the semiconductor element 6.3(Fan Out type, FIG. 6-2), and the case wherein the external terminalsare located at both under and outside the semiconductor element 6.3 (FanIn/Out type, FIG. 6-3) can be used.

Another example of the pad arrangement is the central arrangement shownin FIG. 7. FIG. 7 shows semiconductor element 5.1, and pads 5.1.1. Inthis case, the semiconductor device is composed of the structure shownin FIG. 8. in FIG. 7. FIG. 7 shows semiconductor element 5.1, and pads5.1.1. In this case, the semiconductor device is composed of thestructure shown in FIG. 8.

In accordance with the present invention, the semiconductor element is adevice wherein IC, LSI, and the like, such as memories, logic devices,gate arrays, customs, power transistors, and the like, are formed on awafer comprising semiconductor materials such as Si, GaAs, and the like,and the device has terminals for connecting to a lead, bump, and thelike.

In accordance with the present invention, the semiconductor devicecomprising a tape having a pattern layer is used as an interconnectionbetween the semiconductor element and the mounting substrate, which issuperior in anti-reflow characteristics and connection reliability, maybe provided by using a film material having a modulus of elasticity ofat least 1 MPa in the reflow temperature region (200-250° C.), which isa high temperature region, as the adhesive material while maintainingthe insulation between the circuit tape and the semiconductor element.By using such a film material, a manufacturing method which is superiorin mass productivity to the conventional printing methods can beprovided.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, features and advantages of the presentinvention will be understood more clearly from the following detaileddescription with reference to the accompanying drawings, wherein:

FIG. 1 is a graph indicating temperature dependency of the moduluselasticity of materials;

FIGS. 2a, 2 b, and 2 c are schematic illustrations indicating themanufacturing process of the semiconductor device of the presentinvention, wherein FIG. 2a shows a method wherein the film is adheredpreviously to the circuit tape, FIG. 2b shows a method wherein the filmis adhered previously to the semiconductor element, and FIG. 2c shows amethod wherein the circuit tape and the semiconductor element areadhered together simultaneously via the film;

FIG. 3 is a schematic diagram indicating the continuous process foradhering the film using a long reel;

FIG. 4 is a schematic diagram showing a cross section indicating thecomposition of a circuit tape having a film with an adhesive agentlayer;

FIG. 5 is a schematic diagram of a semiconductor element havingperipheral pads;

FIGS. 6-1, 6-2, 6-3 are schematic cross sections showing the structureof semiconductor devices using the semiconductor elements having theperipheral pads;

FIG. 7 is a schematic diagram showing a semiconductor element havingpads located at the center of the element; and

FIG. 8 schematic cross section showing the structure of a semiconductordevice using a semiconductor element having pads located at the centerof the element.

FIG. 9 shows a semiconductor device with a three layer structure for theadhesive layer. Shown is core layer (e.g., porous supporting layer) 10with adhesive layers 20, 20 on opposite sides of the core layer 10.Semiconductor chip 50 is provided on a semiconductor supportingsubstrate (not shown). Lead 60, including wiring 40, is electricallyconnected to external connecting terminal 80 and electrode 100 of chip50. External connecting terminal 80 is electrically connected to lead 60via a hole in polyimide film 30. Sealing material 70 covers lead 60.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(Embodiment 1)

An epoxy group adhesive film 6.2 (see FIG. 6-1) (made by HitachiChemical Co., Ltd., AS 3000, 50 μm thick) was registered, placed, andadhered between a semiconductor element 6.3 and circuit tape 6.1 at 170°C. for one minute with a pressure of 50 kgf/cm², and was then post-curedat 180° C. for 60 minutes in a constant temperature bath. Subsequently,connecting leads on the circuit tape were electrically connected to padsof the semiconductor element by single point bonding. The connectingportion was encapsulated with an epoxy encapsulant 6.4 (made by HitachiChemical Co., Ltd., RC021C). Finally, the semiconductor device shown inFIG. 6-1 was obtained by fixing the solder balls, which were connectingterminals 6.5 with the mounting substrate, onto the circuit tape 6.1.

After absorbing moisture in a constant temperature bath at 85° C./85% RHfor 168 hours, the obtained semiconductor device was set in an infraredreflow apparatus with a maximum temperature of 245° C., and it wasconfirmed whether the semiconductor device exhibited defects, such asdelamination and voids by foaming the adhesive layer. Furthermore, theconnection reliability between the lead of the semiconductor device andthe solder bump was confirmed. In this case, a woven glass-epoxy copperclad laminate FR-4 (made by Hitachi Chemical Co., Ltd., MCI-E-67) wasused as the mounting substrate. The reliability was evaluated byperforming a thermal cycling test (−55° C.-−150° C., 1000 times).

(Embodiment 2)

A film material 6.2 (see FIG. 6-2) having a three layer structure wasobtained by applying an adhesive agent (made by Hitachi Chemical Co.Ltd., DF335), composed of a die bonding film material, onto bothsurfaces of a polyimide film (made by Ube Kosan Co., Ltd., SGA, 50 μmthick) to a thickness of 50 μm. The obtained film material 6.2 wasregistered and adhered to circuit tape 6.1 at 170° C. for five secondswith a pressure of 30 kgf/cm². Under the above conditions, the unadheredadhesive layer exhibited a sufficient adhesive force to adhere to thesemiconductor element 6.3. The circuit tape attached with the filmmaterial was adhered to the semiconductor element at 200° C. for oneminute with a pressure of 30 kgf/cm² , and was then post-cured at 200°C. for 60 minutes in a constant temperature bath. Subsequently,connecting leads on the circuit tape 6.1 were electrically connected topads of the semiconductor element by gang bonding. The connectingportion was encapsulated with an epoxy encapsulant 6.4 (made by HitachiChemical Co., Ltd., RC021C). Finally, the semiconductor device shown inFIG. 6-2 was obtained by fixing the solder balls, which served asconnecting terminals 6.5 with the mounting substrate, onto the circuittape 6.1. Also shown in FIG. 6-2 is outer frame 6.6.

The reflow characteristics and connection reliability of the lead andthe solder bump of the obtained semiconductor device were confirmed bythe same method as the embodiment 1.

(Embodiment 3)

A low elastic adhesive film 6.2 composed of an epoxy resin and acrylicrubber (made by Hitachi Chemical Co. Ltd., trial product, 150 μm thick)was registered, placed, and adhered between the semiconductor element6.3 and the circuit tape 6.1 at 180° C. for 30 seconds with a pressureof 100 kgf/cm², and was then post-cured at 180° C. for 60 minutes in aconstant temperature bath. Subsequently, connecting leads on the circuittape were electrically connected to pads of the semiconductor element bywire bonding. The connecting portion was encapsulated with a siliconeencapsulant 6.4 (made by Toshiba Silicone Co., Ltd., TSJ 3150). Finally,the semiconductor device shown in FIG. 6-3 was obtained by fixing thesolder balls, which served as connecting terminals 6.5 with the mountingsubstrate, onto the circuit tape 6.1. Also shown in FIG. 6-3 is outerframe 6.6.

The reflow characteristics and connection reliability of the lead andthe solder bump of the obtained semiconductor device were confirmed bythe same method as the embodiment 1.

(Embodiment 4)

A film material having a three layer structure was obtained by adheringa low elastic adhesive film composed of epoxy resin and acrylic rubber(made by Hitachi Chemical Co. Ltd., trial product, 50 μm thick) to bothsurfaces of a woven glass-epoxy resin laminate (obtained by eliminatinga copper cladding by etching from both surfaces of MCL-E-679 made byHitachi Chemical Co., Ltd.). The film material was registered, placed,and adhered between the semiconductor element and the circuit tape at200° C. for 20 seconds with a pressure of 80 kgf/cm², and was thenpost-cured at 180° C. for 60 minutes in a constant temperature bath.Subsequently, connecting leads on the circuit tape were electricallyconnected to pads of the semiconductor element by single point bonding.The connecting portion was encapsulated with a silicone encapsulant(made by Toshiba Silicone Co., Ltd., TSJ 3153). Finally, thesemiconductor device shown in FIG. 8 was obtained by fixing the solderballs, which serve as connecting terminals with the mounting substrate,onto the circuit tape.

The reflow characteristics and connection reliability of the lead andthe solder bump of the obtained semiconductor device were confirmed bythe same method as the embodiment 1.

(Embodiment 5)

A LOC (Lead on chip) Film (made by Hitachi Chemical Co. Ltd., HM122U,100 μm thick) having a three layer structure was registered and adheredto the circuit tape at 300° C. for 2 seconds with pressure of 150kgf/cm². In the adhering process, the film was stamped out into adesignated shape using the long scale apparatus shown in FIG. 3, and thestamped film was adhered to the circuit tape continuously. Because theadhesive layer of the film was made of a thermoplastic resin, theunadhered portion of the adhesive layer still had a sufficient adheringforce to the semiconductor element.

The circuit tape with the film material was adhered to the semiconductorelement at 300° C. for 10 minutes with a pressure of 100 kgf/cm².Subsequently, connecting leads on the circuit tape were electricallyconnected to pads of the semiconductor element by single point bonding.The connecting portion was encapsulated with an epoxy encapsulant (madeby Hokuriku Toryo Co., Ltd. Chip coat 8107). Finally, the semiconductordevice shown in FIG. 6-1 was obtained by fixing the solder balls, whichserved as connecting terminals with the mounting substrate, onto thecircuit tape.

The reflow characteristics and connection reliability of the lead andthe solder bump of the obtained semiconductor device were confirmed bythe same method as the embodiment 1.

(Embodiment 6)

A thermoplastic polyimide film (made by Mitsui Toatsu Chemicals, Inc.,Regulus PI-UAY, 100 μm thick) was registered and adhered to thesemiconductor element at 250° C. for 2 seconds with a pressure of 30kgf/cm². The film had a sufficient adhesive force to adhere to thecircuit tape.

The semiconductor element with the film material was adhered to thecircuit tape at 250° C. for 10 minutes with a pressure of 20 kgf/cm².Subsequently, connecting leads on the circuit tape were electricallyconnected to pads of the semiconductor element by wire bonding. Theconnecting portion was encapsulated with an epoxy encapsulant (made byHokuriku Toryo Co., Ltd. Chip coat 8107). Finally, the semiconductordevice shown in FIG. 6-2 was obtained by fixing the solder balls, whichserved as connecting terminals with the mounting substrate, onto thecircuit tape.

The reflow characteristics and connection reliability of the lead andthe solder bump of the obtained semiconductor device were confirmed bythe same method as the embodiment 1.

(Embodiment 7)

A film material composed of a three layer structure having two differentkinds of adhesive layers was obtained by applying a fluorine-containingpolyimide (a reactant of hexafluorobisphenol AF andbis(4-aminophenoxyphenyl)hexafluoropropane, glass transition temperature260° C.) onto one surface of a polyimide film (made by Ube Kosan Co.Ltd., SGA, 50 μm thick) to a thickness of 50 μm, and apolyetheretherketone (a reactant of dihydroxy-naphthalene anddifluorobenzophenone, glass transition temperature 154° C.) onto theother surface of the polyimide film to a thickness of 50 μm.

The obtained film material was registered and adhered to the circuittape using the adhesive layer having a lower glass transitiontemperature. The adhesion condition was at 200° C. for one minute with apressure of 30 kgf/cm². Because the adhesive layer of the film wascomposed of a thermoplastic resin, the adhesive layer had a sufficientadhering force to adhere to the semiconductor element. The circuit tapewith the film material was adhered to the semiconductor element at 300°C. for ten seconds with a pressure of 80 kgf/cm². Subsequently,connecting leads on the circuit tape were electrically connected to padsof the semiconductor element by gang bonding. The connecting portion wasencapsulated with an epoxy encapsulant (made by Hokuriku Toryo Co. Ltd.,Chip coat 8107). Finally, the semiconductor device shown in FIG. 6-3 wasobtained by fixing the solder balls, which served as connectingterminals with the mounting substrate, onto the circuit tape.

The reflow characteristics and connection reliability of the lead andthe solder bump of the obtained semiconductor device were confirmed bythe same method as the embodiment 1.

(Embodiment 8)

A silicone adhesive agent (made by Shinetsu Chemical Co. Ltd., KE1820)was applied onto one surface of a silicone film (made by Toray DowCorning Silicone Co. Ltd., JCR6126, 150 μm thick, press-fabrication) toa thickness of 20 μm. Then, the silicone film was registered and adheredto they circuit tape. The adhesion condition was at 150° C. for oneminute with a pressure of 30 kgf/cm². Furthermore, in order to adhere tothe semiconductor element, the silicone adhesive agent (made by ShinetsuChemical Co. Ltd., KE1820) was applied onto the other surface of thesilicone film to a thickness of 20 μm, and the circuit tape attachedwith the film material was adhered to the semiconductor element. Theadhesion condition was at 200° C. for 30 seconds with a pressure of 20kgf/cm². Subsequently, connecting leads on the circuit tape wereelectrically connected to pads of the semiconductor element by gangbonding. The connecting portion was encapsulated with a siliconeencapsulant (made by Toray Dow Corning Silicone Co. Ltd., DA 6501).Finally, the semiconductor device shown in FIG. 8 was obtained by fixingthe solder balls, which serve as connecting terminals with the mountingsubstrate, onto the circuit tape.

The reflow characteristics and connection reliability of the lead andthe solder bump of the obtained semiconductor device were confirmed bythe same method as the embodiment 1.

(Embodiment 9)

Porous polytetrafluoroethylene (made by Japan Gore-tex Inc., 190 μmthick), both surfaces of which were applied with BT resin(Bismaleimide-Triazine resin), was registered and adhered to the circuittape. The adhesion condition was at 150° C. for one minute with apressure of 30 kgf/cm². Because the adhesive layer of the film was in aB stage condition (half-cured condition), the adhesive layer had asufficient adhering force to adhere to semiconductor element. Theadhesion of the circuit tape with the film material to the semiconductorelement was conducted at 200° C. for 2 minutes with a pressure of 70kgf/cm². Subsequently, connecting leads on the circuit tape wereelectrically connected to pads of the semiconductor element by gangbonding. The connecting portion was encapsulated with an epoxyencapsulant (made by Hitachi Chemical Co., Ltd. RO21C.). Finally, thesemiconductor device shown in FIG. 6-1 was obtained by fixing the solderballs, which were connecting terminals with the mounting substrate, ontothe circuit tape.

The reflow characteristics and connection reliability of the lead andthe solder bump of the obtained semiconductor device were confirmed bythe same method as the embodiment 1.

(Embodiment 10)

A sticky tape having a three layer structure (made by TeraokaSeisakusyo, Ltd., Tape No. 760, 145 μm thick, silicone adhesive agentwas applied onto both surfaces of Kapton film (commercial name by DuPont)) was registered and adhered to the circuit tape at roomtemperature for 5 seconds with a pressure of 50 kgf/cm². In the adheringprocess, the film was stamped out into a designated shape using the longscale apparatus shown in FIG. 3, and the stamped film was adhered to thecircuit tape continuously. Because the adhesive layer of the film wasmade of a sticky resin, the unadhered portion of the adhesive layerstill had a sufficient adhering force to adhere to the semiconductorelement.

The circuit tape with the film material was adhered to the semiconductorelement at room temperature for 10 seconds with a pressure of 5 kgf cm².Subsequently, connecting leads on the circuit tape were electricallyconnected to pads of the semiconductor element by single point bonding.The connecting portion was encapsulated with a silicone encapsulant(made by Toshiba Silicone co. Ltd. TSJ 3150). Finally, the semiconductordevice shown in FIG. 6-2 was obtained by fixing the solder balls, whichserve as connecting terminals with the mounting substrate, onto thecircuit tape.

The reflow characteristics and connection reliability of the lead andthe solder bump of the obtained semiconductor device were confirmed bythe same method as the embodiment 1.

(Embodiment 11)

A cohesive tape having a three layer structure (150 μm thick, butadieneadhesive agent was applied onto both surfaces of unwoven aramide cloth(100 μm thick)) was registered and adhered between semiconductor andcircuit tape at room temperature for 5 seconds with a pressure of 50kgf/cm². Under the above condition, some correction of the registrationwas possible, because the adhesive layer was still in a cohesivecondition. Then, the adhesive layer of the film was cured at 180° C. for60 minutes in a constant temperature bath to form a connecting statehaving a three dimensional crosslinking structure, because the adhesivelayer was made of a cohesive resin.

Subsequently, connecting leads on the circuit tape were electricallyconnected to pads of the semiconductor element by single point bonding.The connecting portion was encapsulated with a silicone encapsulant(made by Toshiba Silicone Co., Ltd. TSJ 3150). Finally, thesemiconductor device shown in FIG. 6-3 was obtained by fixing the solderballs, which serve as connecting terminals with the mounting substrate,onto the circuit tape.

The reflow characteristics and connection reliability of the lead andthe solder bump of the obtained semiconductor device were confirmed bythe same method as the embodiment 1.

(Embodiment 12)

A polyamic acid was prepared by reacting an equivalent of benzophenonetetracarboxylic acid dianhydride (made by Wako Pure Chemicals) andbis(4(2-aminophenoxyphenyl)ether) (synthetic chemical) at 5° C. indimethylacetamide. Then, the reactant was heated at 250° C. to obtainpolyimide. The obtained polyimide 100 g was mixed with4,4′-glycidyl-3,3′, 5,5′-tetramethylbiphenylether (made by Yuka Shell)19.5 g, phenol novolac (made by Meiwa Kasei) 10.6 g, andtriphenylphosphate (made by Wako Pure Chemicals) 0.2 g as a catalyst indimethylacetamide to obtain a varnish containing a non-volatilecomponent of 20% by weight. A film 100 μm thick was prepared with theobtained varnish.

The prepared film was registered and adhered to the circuit tape. Theadhesion condition was at 170° C. for ten seconds with a pressure of 30kgf/cm². Under the above conditions, the unadhered portion of theadhesive layer had a sufficient adhering force to adhere withsemiconductor if element. The adhesion of the circuit tape with the filmmaterial to the semiconductor element was conducted at 200° C. for oneminute with a pressure of 30 kgf/cm². Subsequently, a post-curing wasperformed at 200° C. for 60 minutes in a constant temperature bath.Then, connecting leads on the circuit tape were electrically connectedto pads of the semiconductor element by gang bonding. The connectingportion was encapsulated with an epoxy encapsulant (made by HitachiChemical Co., Ltd. RC021C.). Finally, the semiconductor device shown inFIG. 6-2 was obtained by fixing the solder balls, which serve asconnecting terminals with the mounting substrate, onto the circuit tape.

The reflow characteristics and connection reliability of the lead andthe solder bump of the obtained semiconductor device were confirmed bythe same method as the embodiment 1.

(Embodiment 13)

A film having a three layer structure was prepared by applying thevarnish obtained in the embodiment 12 onto the one surface of polyimidefilm (made by Ube Kosan Co. Ltd., SGA, 50 μm thick) to a thickness of 20μm (thermosetting resin component), and the fluorine-containingpolyimide, i.e. the varnish prepared in the embodiment 7, (the reactantof hexafluorobisphenol AF andbis(4-aminophenoxyphenyl)hexafluoropropane, with a glass transitiontemperature of 260° C.) was applied onto the other surface of thepolyimide film to a thickness of 10 μm (thermoplastic resin component).The film was registered and adhered to the circuit tape at the surfacewhere the thermosetting resin component was applied. The adhesioncondition was at 170° C. for 10 seconds with a pressure of 30 kgf/cm².Then, a post-curing was performed at 200° C. for 60 minutes in aconstant temperature bath. Subsequently, the semiconductor element wasadhered to the surface where the thermoplastic resin component wasapplied. The adhesion condition was at 350° C. for 2 seconds with apressure of 80 kgf/cm². Then, connecting leads on the circuit tape wereelectrically connected to pads of the semiconductor element by gangbonding. The connecting portion was encapsulated with an epoxyencapsulant (made by Hokuriku Toryo chip coat 8107). Finally, thesemiconductor device shown in FIG. 6-2 was obtained by fixing the solderballs, which serve as connecting terminals with the mounting substrate,onto the circuit tape.

The reflow characteristics and connection reliability of the lead andthe solder bump of the obtained semiconductor device were confirmed bythe same method as the embodiment 1.

(Comparative Example 1)

An elastomer of 150 μm thickness was formed by registering siliconeresin (made by Toray Dow Corning Silicone Co. Ltd., JCR 6126) with thecircuit tape and printing using metal masks. After the formation,post-curing was performed at 150° C. for 60 minutes in a constanttemperature bath. Then, the flatness of the elastomer was determinedusing a laser film thickness measuring apparatus. A silicone adhesiveagent (made by Sinetsu Chemical Co. Ltd., KE 1820) was applied onto thesurface of the elastomer a thickness of 20 μm as an adhesive layer forcausing the semiconductor element to adhere to the circuit tape havingthe elastomer, and the circuit tape was registered and adhered to thesemiconductor element. The adhesion was carried out at 150° C. for oneminute with a pressure of 30 kgf/cm². Then, connecting leads on thecircuit tape were electrically connected to pads of the semiconductorelement by gang bonding. The connecting portion was encapsulated with asilicone encapsulant (made by Toshiba Silicone, TSJ 3150). Finally, thesemiconductor device shown in FIG. 6-1 was obtained by fixing the solderballs, which serve as connecting terminals with the mounting substrate,onto the circuit tape.

The reflow characteristics and connection reliability of the lead andthe solder bump of the obtained semiconductor device were confirmed bythe same method as the embodiment 1.

(Comparative Example 2)

A film having a three layer structure was prepared by applying athermoplastic resin (polyamide 12, m.p. 175° C.) having a melting pointequal to or lower than 200° C. onto both surfaces of a polyimide film(made by Ube Kosan Co. Ltd., SGA, 50 μm thick) as adhesive layers (30 μmthick). The film having the three layer structure was used to prepare asemiconductor device using the same method as the embodiment 1, and thereflow characteristics and connection reliability of the lead and thesolder bump of the obtained semiconductor device were confirmed by thesame method as the embodiment 1.

(Comparative Example 3)

A film having a three layer structure was prepared by applying an epoxyresin (made by Hitachi Chemical Co., Ltd., RO21C) having a high modulusof elasticity at room temperature onto both surfaces of a polyimide film(made by Ube Kosan Co. Ltd., SGA) as adhesive layers (20 μm thick). Thefilm having the three layer structure was used to prepare asemiconductor device by the same method as the embodiment 1, and thereflow characteristics and connection reliability of the lead and thesolder bump of the obtained semiconductor device were confirmed by thesame method as the embodiment 1.

TABLE 1 Elastic modulus (MPa) Thermal cycling Adhesive test (1000cycles) layers Lead Bump Adhesive (average open open film of 200˜ Reflowfailure failure (25° C.) 250° C.) test (%) (%) Emb.* 1  788 4.3 No void0 0 Emb. 2 5000 1.5 No void 0 0 Emb. 3  960 3.6 No void 0 0 Emb. 4 41903.6 No void 0 0 Emb. 5 3750 13 No void 0 0 Emb. 6 3500 100 No void 0 0Emb. 7 3500 2000, 15 No void 0 0 Emb. 8  10 2.5 No void 0 0 Emb. 9 2000100 No void 0 0 Emb. 10  20 2.5 No void 0 0 Emb. 11  30 3.5 No void 0 0Emb. 12  850 8.5 No void 0 0 Emb. 13 3300 2000, 8.5 No void 0 0 Com.1 10 2.5 No void 10  0 Com. 2 1400 −0 Void 5 0 Com. 3 11000  1100 No void80  100  *: Embodiment, : Comparative example.

Flatness of the elastomer: High and low difference of comparativeexample 1 was 50 μm to thickness of 150 μm, and all other samples within5 μm.

Reflow test condition: Pretreatment: 85° C./85% RH, 48 hours, Waterabsorption 240° C.×3 times, Infrared oven.

In accordance with the present invention, a semiconductor device isprovided, wherein tape material having a circuit layer and asemiconductor element are electrically connected, an external terminalfor effecting electrical connection with the mounting substrate isprovided on the circuit tape, and a film material is used as thematerial for bonding the circuit tape and the semiconductor element inan insulating manner, resulting in a semiconductor device which issuperior in anti-reflow property due to the use of the film material forthe adhesion, of which the modulus of elasticity in the reflowtemperature range is at least 1 MPa. A manufacturing method is alsoprovided which is superior in mass productivity by using a film materialat a portion for buffering thermal stress generated by a difference inthermal expansion of the semiconductor element and the mountingsubstrate.

The film material is superior in flatness, and a high and low differencewithin 5 μm can be ensured for a thickness of 150 μm, and so amanufacturing method which is superior in workability can be provided.In accordance with the stress buffering effect of the film material, theconnection reliability of both the lead portion which electricallyconnects the circuit tape and the semiconductor element, and bump whichelectrically connects the semiconductor device and the mountingsubstrate can be satisfied simultaneously in a temperature cycling test.

What is claimed is:
 1. A semiconductor device, comprising: a semiconductor element; a circuit tape having a circuit layer; external terminals for electrically connecting the circuit tape to a mounting substrate; and an adhesive film for adhering said circuit tape to said semiconductor element such that the circuit tape is insulated from the semiconductor element, wherein said circuit layer is electrically connected to a pad of said semiconductor element and to said external terminals, and said adhesive film is porous.
 2. A semiconductor device as claimed in claim 1, wherein said adhesive film includes a three-layer structure having a porous support layer and two adhesive layers which are respectively applied onto both sides of said porous support layer.
 3. A semiconductor device as claimed in claim 1, wherein said adhesive film has a structure of an adhesive agent impregnated into a porous support layer.
 4. A semiconductor device as claimed in claim 1, wherein said circuit layer of said circuit tape is electrically connected to said pad of said semiconductor element by a wire bonding.
 5. A semiconductor device as claimed in claim 1, wherein the porous adhesive film includes a material selected from the group consisting of polyimide, epoxy, polyethylene terephthalate, cellulose, acetate, and fluorine-containing polymer.
 6. A semiconductor device as claimed in claim 1, wherein the porous adhesive film includes a porous polytetrafluoroethylene layer, both sides of which have had bismaleimide-triazine resin applied thereto.
 7. A semiconductor device comprising: a semiconductor element; a circuit tape having a circuit layer on a dielectric film; an adhesive film, positioned between said semiconductor element and said circuit tape, for operating as a stress relaxing layer for relaxing thermal stress; and external terminals for electrically connecting the circuit tape to a mounting substrate, wherein said adhesive film comprises a porous support, a plane having pads of said semiconductor element is adhered to said circuit tape by said adhesive film such that the circuit tape is insulated from the semiconductor element, connecting leads on said circuit tape are electrically connected to said pads on said semiconductor element, and said external terminals for connecting to said mounting substrate are formed on said circuit tape.
 8. A semiconductor device as claimed in claim 7, wherein said adhesive film has a structure of an adhesive agent impregnated into a porous support layer.
 9. A semiconductor device as claimed in claim 7, wherein said adhesive film includes a three-layer structure having a porous support layer and two adhesive layers which are respectively applied onto both sides of said porous support layer.
 10. A semiconductor device as claimed in claim 7, wherein a portion of each of said pads of said semiconductor element connecting to said circuit layer of said circuit tape is sealed with an insulating material.
 11. A semiconductor device as claimed in claim 10, wherein said insulating material is an epoxy material.
 12. A semiconductor device comprising: a semiconductor element; a circuit tape having a circuit layer on a dielectric film; an adhesive film positioned between said semiconductor element and said circuit tape for operating as a stress relaxing layer for relaxing thermal stress; and external terminals for electrically connecting the circuit tape to a mounting substrate, wherein pads are arranged at one of a middle and a periphery of said semiconductor element, said adhesive film comprises a porous support, said circuit layer is connected to a plane having said pads of said semiconductor element via said adhesive film such that said circuit layer is insulated from the semiconductor element, connecting leads on said circuit tape are connected to said pads of said semiconductor element, and external terminals for electrically connecting the circuit tape to a mounting substrate are formed on said circuit tape.
 13. A semiconductor device as claimed in claim 12, wherein said external terminals for electrically connecting the circuit tape to said mounting substrate are formed at a bottom side of said semiconductor element.
 14. A semiconductor device as claimed in claim 12, wherein said external terminals for electrically connecting the circuit tape to said mounting substrate are formed at an exterior side of said semiconductor element.
 15. A semiconductor device as claimed in claim 12, wherein said external terminals for electrically connecting the circuit tape to said mounting substrate are formed at a respective one of a bottom side and an exterior side of said semiconductor element.
 16. A semiconductor device as claimed in claim 12, wherein a portion of each of said pads of said semiconductor element connecting to said circuit layer is sealed with an insulating material.
 17. A semiconductor device comprising: a semiconductor element; a circuit tape having a circuit layer on a dielectric film; an adhesive film for connecting said semiconductor element to said circuit tape such that the circuit tape is insulated from the semiconductor element; external terminals for electrically connecting the circuit tape to a mounting substrate; and an outer frame covering planes of said semiconductor element except one plane, wherein plural pads are provided at a periphery of said semiconductor element which is not covered with said outer frame, the plural pads being provided in a plane, said circuit tape is connected to the plane having said pads of the semiconductor element and to said outer frame at an outer side of the plane having said pads, by said adhesive film, said adhesive film comprises a porous support, said circuit layer of said circuit tape is electrically connected to said plural pads of said semiconductor element, a portion of each of said pads of said semiconductor element electrically connecting to said circuit layer is sealed with an insulating material, and said plural external terminals for electrically connecting the circuit tape to said mounting substrate are formed on said circuit tape arranged at the outer frame.
 18. A semiconductor device comprising: a semiconductor element; a circuit tape having a circuit layer on a dielectric film; an adhesive film for connecting said semiconductor element to said circuit tape such that the circuit tape is insulated from the semiconductor element; external terminals for electrically connecting the circuit tape to a mounting substrate; and an outer frame covering planes of said semiconductor element except one plane, wherein plural pads are provided at a periphery of said semiconductor element which is not covered with said outer frame, the plural pads being provided in a plane, said circuit tape is connected to the plane having said pads of the semiconductor element and to said outer frame at an outer side of the plane having said pads, by said adhesive film, said adhesive film comprises a porous support, said circuit layer of said circuit tape is electrically connected to said plural pads of said semiconductor element, a portion of each of said pads of said semiconductor element electrically connecting to said circuit layer is sealed with an insulating material, and said plural external terminals for electrically connecting the circuit tape to said mounting substrate are formed on said circuit tape arranged both at the outer frame and at the semiconductor element. 